Rotating in Gimbal coordinate space

- [Voiceover] The next step that we want to takein setting up our hierarchyis to take a look at something called gimbal rotationsand this really comes into playwhen you're animating an articulated hierarchysuch as this.Let's select one of these shoulder objects,get in close on thatand grab the Rotate tooland if we're in local coordinate space,that seems to indicatethat we're operating in the space of the objectand if I rotate around x,we can see that that objectis aligned with the rotate gizmo.

You can see that more clearly hereas I move to the front.Well, local mode seems like a good idea for animationand generations of animators in 3Dhave been using local mode forever.However, local mode is actually really problematicand that's because it's kind of a fake coordinate space.It's not the actual coordinate spaceof the object.It looks like it is but it isn't reallyand to illustrate that,I want to open upthe Transform Type-in dialogand that is the little floating windowthat shows us the transform valuessimilar to what we see down herein the Transform Type-in areabut this is just going to give us a lot more control.

So I'm going to right click on the Rotate tooland we have the Transform Type-in dialogand this shows us the valuesin the currently selected transform coordinate spaceor reference coordinate space.Interestingly, if you're in local modeand for example, you rotate in an axis,notice that although we're seeing the object rotate,we're seeing the numbers updatein that heads up displaybut the Transform Type-in dialogshows values of zeroand that's just kind of a quirk of 3ds Max.

The Transform Type-in dialog in local spaceis always going to show values of zero.I'm going to undo that with Control Z.Going up here and changing thisto a different reference coordinate system,let's try Parent and that's a useful onebecause when we rotate an objector transform or scale it,in reality we're actually rotating and scaling itin its parent coordinate space,not in its own local space.Currently, this object does not have a parentand so the parent is the worldand when I choose parent,I'm actually really working in world coordinate space.

This is telling me what the absolute rotation valuesof that object are.Okay, now, let's see what the issue iswhen we work in either local or any other modeand I turn off my angle snapsand I'll go over here and rotate in ywhich is the green circle hereand that looks fine.Okay, undo that, Control Z.Let's try rotating in x which is the red circle.And although I'm thinkingI'm only rotating in one axisbecause I've only selected the red axis,look at what's going onin that rotate Transform Type-in dialog.

It's actually rotating the objectin all three axes.This is actually a real problembecause if you rotate in local mode or parent mode,you might think that you're only animating in one axiswhen in fact under the hood,you're actually rotating in two or even three axesand you might say, oh, well, whatever.How does that matter?Why do I care?Well, you care becauseif you're actually key framing or animatingin three axes simultaneouslythen you cannot control the behavior of the objectand what will happenis that if you make subsequent key framesor animation key pointsthen the object will animate in three axes at onceand it will move in unpredictable directionsand generations of 3D animatorshave bashed their heads against their computer screenswhen this happened.

They rotate in one axis,they make a key frameand they think they're goodand then they play the animation backand the object spins uncontrollably wildlyand just goes crazy.Alright, so there is a solution to thisand that is that we want to make surethat we're only rotating in one axis at a time.I'll undo that rotation that I just didand the key here is just to switch overto the reference coordinate systemlabeled Gimbaland that is the magic solution to all these problems.I never use local coordinate space.

I never use parent coordinate space.Whenever animating rotations,I'm always in Gimbal spaceand now if I rotate around the x axis,only the x axis updatesor if I rotate around the y axis,only y updates.Likewise with z.This is super importantand if you are in Gimbal mode when you do rotations,you'll actually be able to control the rotationsand you can key frame in a single axisand not have your object spin around in crazy directions.

By the way, if you're wondering what a gimbal is,it's a real word object.It's a series of three interlocking ringsthat's used to do thingslike stabilize a compass in an airline cockpitas the airplane tilts up and downand goes in different directions.So the Gimbal mode hereevokes the actual real gimbal in the real worldbecause we have three rings here,one for each axis.Alright, so the moral of the story here is thatif you want to have predictable rotations,always use Gimbal mode.

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Released

4/18/2016

3ds Max is best known for its modeling and rendering tools. These strengths come into play in architecture, manufacturing, game development, industrial design, and motion graphics. There are dozens of features and techniques to master, from sculpting and texturing to lighting and rendering. 3ds Max 2017 Essential Training covers "Max" from the ground up, providing an overview of the entire package as well as essential skills that 3D artists need to create professional models and animations.

Learn how to get around the 3ds Max interface and customize it to suit your production pipeline. Discover how to model different objects using splines, NURBS, polygons, subdivision surfaces, and tools such as Paint Deform. Then find out how to construct hierarchies, add cameras and lights to a scene, and animate with keyframes. Author Aaron F. Ross also takes an-depth look at materials and texture mapping as well as the rendering options in 3ds Max 2017, including the new Autodesk Raytracer (ART) renderer.